The present invention is involved in the enclosing and housing of computer gear, communications gear, and other electronic equipment. Exemplary of the present invention are U.S. Pat. Nos. 2,991,140 and 3,034,844, both expired and both assigned to the assignee of this Application.
Of the subject patents, particularly U.S. Pat. No. 2,991,940, when developed, was the state of the art even at the time the Patent Application was filed. It did meet certain static strength requirements which were adequate at the time.
Since the development of U. S. Pat. Nos. 2,991,940; 3,034,844 and 3,087,768, however, a whole new industry of computers and communications gear have evolved. Some of these, if subjected to earthquake tremors or indeed an earthquake, can be substantially damaged. In addition, they are sensitive to spurious electro-type emissions. The subject of RFI shielding was in its infancy at the time of the development of the products of the subject three state of the then art patents.
In addition, including the various practical needs for such an enclosure, there are currently four requirements based upon national and international standards. They are the following:
1. Bell Core NEBS, which is a seismic test; PA1 2. FCC primary RFI test; PA1 3. NEMA test--NEMA certification capabilities, leakage, dust and contaminant penetration, and the like; and PA1 4. IEC--These are certain international requirements which may or may not be included in the three foregoing requirements.
Severe earthquakes, in addition to destruction of homes, highways and office buildings, have resulted in the twisting and mangling of computers and related communications gear. Subsequent damage from after shocks have also been severe. Had the electronics been housed in a stronger housing, however, such damage could have been mitigated, if not inhibited or eliminated in some cases. Therefore, it is highly desirable to develop a modular enclosure which, because of its modularity, renders it relatively inexpensive to manufacture. Moreover, it is highly desirable to develop such a modular enclosure which is resistant to lateral loads, torsional loads, vibratory loads, and other severe conditions which may be anticipated from an earthquake or, indeed, from nearby exploding bombs where a military installation is involved. In addition, such a modular enclosure should lend itself to RFI shielding at least for primary purposes.
What is further needed, is a plurality of such cabinets which can be linked together, side by side, two or more, which afford the same or greater strength capabilities as well as conforming to the four standards set forth above.